Many situations arise where vibration-damping isolation of a mattress or seat cushion from its support frame would be highly desirable. Long-distance trucking operators commonly use team drivers who take turns driving and sleeping in a bed provided for that purpose behind the seats in the cab of the tractor that pulls the trailer. Obtaining adequate sleep in a tractor cab is difficult, however, owing to the high level of vibration to which the cab is subjected, whether moving or parked with the engine running. Existing sleeper beds for tractor cabs have mattresses that absorb some of the vibration, but much of it is transmitted to the driver occupying the bed, keeping him from obtaining uninterrupted sleep for an extended period. As a result, the driver who is attempting to sleep may be unable to do so to the extent necessary to relieve fatigue. The implications of having a fatigued driver instead of a fully rested one at the wheel are readily apparent. The fully rested driver is much less likely to become involved in an accident. Also, the fully rested driver will function more efficiently, which means increased revenue to the trucking company by helping him to make local points and schedules on time and producing a better attitude toward taking care of the truck, which is a very large investment for the owner.
Magnetic cushioning of mattresses and seats is disclosed in certain prior patents. U.S. Pat. No. 3,604,027 shows the use of electromagnets mounted on spaced-apart plates in a seat cushion, one plate being secured to the seat frame and the other to the underside of the seat cushion. Mechanical springs coupling the upper and lower plates are also provided. This structure does not provide effective isolation of the cushion from vibrations to which the frame might be subjected because the vibrations would be transmitted through the springs. Another approach is disclosed in West Germany Patent No. 2,738,529 wherein a mattress employs two layers of large numbers of circular magnets supported on sheets of material in spaced-apart relation with magnet faces of like polarity opposing one another so as to provide repulsion between the two layers, thus cushioning the top of the mattress when it is supporting the weight of a sleeper. The mattress shown in this patent also fails to provide isolation of the mattress top from vibrations to which the supporting frame might be subjected, and therefore it would not be effective for vibration environments such as exist in sleeper cabs on trucks. As shown in the drawing, the top covering of the mattress of this patent, which has the top layer of magnets secured to its underside, is secured to a side frame support so that vibrations from the frame support would be readily transmitted to the sleeper.